Abstract: The present invention provides silica shell encapsulated polyaromatic-core microparticles and methods for producing and using the same. In particular, the silica shell encapsulated polyaromatic-core microparticles of the invention are hydrophilic microparticle scintillators comprising (i) polyaromatic-core microparticle (1), wherein said polyaromatic-core microparticle (1) is doped with a scintillator material (2); and (ii) a silica-shell portion (3) encapsulating said polyaromatic-core microparticle (1), wherein said silica-shell portion (3) comprises an outer surface (4). The polyaromatic-core portion is formed from an aromatic vinyl compound selected from the group consisting of styrene, vinyl toluene, and a mixture thereof.

Abstract: The present invention provides a process for producing a nanocomposite particle (“nanoSCINT particle”) adapted for use in scintillating proximity assay in a relatively high quantity. The nanoSCINT particle comprises a silica shell that encapsulates a nanoparticle organic polymer that is doped with at least one scintillating compound. In particular, the process of the invention includes adding a plurality of batch-wise portions of a polymerization initiator to an emulsion comprising a relatively high amount of polymerizable organic compound to produce a nanoparticle organic polymer, which is then doped with at least one scintillating compound, and then encapsulated with a silica shell to produce nanoSCINT particles in gram quantities in a single process. Unlike conventional methods, a single process of the invention provides at least about 5 g, typically at least about 7.5 g, and often at least about 10 g of nanocomposite particles.